Numerous products for water-containing vessels (such as but not limited to swimming pools, spas, and hot tubs) utilize electrical energy for operation. This electricity conventionally is supplied via residential or commercial electrical mains. U.S. Pat. No. 6,981,650 to Uy, et al., for example, describes a heater for a pool or spa designed to operate using power furnished by electrical mains (and passed through a voltage step-down transformer). Controller systems operable using electrical mains or other power sources are discussed in, for example, U.S. Pat. No. 7,398,138 to Emery, et al., while an exemplary electrically-powered automatic swimming pool cleaner is disclosed in U.S. Pat. No. 7,117,554 to Pichon. The entire contents of each of the Uy, Emery, and Pichon patents are incorporated herein by this reference.
In some situations, solar power alternatively may be used to generate electricity. U.S. Pat. No. 3,845,291 to Portyrata addresses yet another approach, using a water-powered turbine to power a generator. The generator in turn directly powers a lamp assembly for illuminating portions of a swimming pool. In the system of the Portyrata patent, the lamp assembly is in-line with the flowing water; indeed, the lens housing of the assembly must include an outlet so that water may exit the assembly and return to the swimming pool. A similar in-line, direct-power system is disclosed in U.S. Pat. No. 4,616,298 to Bolson, with the exiting water emitted as a “fine decorative spray” or, apparently, in conjunction with fire-suppression sprinklers. See Bolson, col. 4, 11. 30-32; col. 5, 11. 4-7. The entire contents of each of the Portyrata and Bolson patents are incorporated herein by this reference.
Omitted from these latter two patents is any contemplation of non-in-line, indirect powering of electrical devices within or associated with fluid-containing vessels. Non-in-line operation, for example, avoids need necessarily to seal any water-sensitive components of the devices from the water flowing therethrough. It also avoids impeding water flow that would occur by forcing the water to exit small or fine openings, as in the lamp assemblies of the Portyrata and Bolson patents. Providing indirect powering permits systems to store electrical energy in batteries or similar storage units for later use.